Is PowerTop / TLP Still Useful To Save Power On Linux Laptops?

First up is a look at the Lenovo ThinkPad X1 Carbon while idling at the desktop for five minutes on battery.

Between Linux 4.13 and 4.15 Git, there wasn't much of a difference in the power usage. But when using TLP or PowerTop, there was still significant power savings. The average power draw dropped from 7.1 Watts down to 5.7 Watts with the minimum power draw dropping from 7.0 Watts down to 5.6 Watts. Quite an easy power saving.

And then under load when running the same benchmarks, there was some small savings... The average power use under load was 16.6~16.7 Watts while with TLP or PowerTop it dropped to 15.8 Watts. The peak and minimum power draws were of similar nature when applying the TLP/PowerTop power saving tweaks.

These power-saving tweaks hadn't yielded any degradation in performance:

All of those individual details can be found via this OpenBenchmarking.org result file.